Fig. 7: A PTMs-monitoring model in which IPA1 promotes grain yield and disease resistance to M. oryzae.

Under normal conditions, IPA1 activates the promoters of various yield-related genes, promoting plant growth and yield. Upon M. oryzae challenge, IPA1 goes through four statuses: plain IPA1, ubiquitinated IPA1, phosphorylated IPA1, and ubiquitinated and phosphorylated IPA1. First, both plain IPA1 and ubiquitinated IPA1 promote expression of yield-related genes to increase grain yield. Second, phosphorylated IPA1 binds to promoters of the immune-related genes, including WRKY45 promoter, without transactivation activity. Third, ubiquitinated and phosphorylated IPA1, which represents “blast-activated” IPA1, binds to and transactivates immune-related genes to enhance host resistance to M. oryzae.